Looper-thread controller for sewing machines



- 1,542,856 J. E. CHALMAN LOOPER THREAD CONTROLLER FOR SEWING MACHINES June 23, 1925.

4 Sheets-Sheet 1 Filed Feb. '7, 1923 June 23, 1925.

Filed Feb. Z, 1923 4 Sheets-Sheet 2 AW W A June 23, 1925.

' J. E. CHALMAN Loor'rn THREAD coumoman FOR sswme MACHINES Filed Feb. 7, 1923 4 Sheets-Sheet 3 Em ,ww kw J. E. CHALMAN LOOPER THREAD CONTROLLER FOR SEWING MACH INES June 23, 1925.

Filed Feb. '7, 1923 4 Sheets-Sheet 4 Patented June 23, 1925 UNITED STATES 1,542,856 PATENT oFFrcE.

' "JOHN E. CHALMAN, OF CHICAGO, ILLINOIS, ASSIGNOR TO UNION SPECIAL 'MACHINE COMPANY, or CHICAGO, ILLINO A CORPORATION 01? ILLINOIS- LOOPER-THREAD CONTROLLER IE OB SEWING MlACI-IINES.

Application filed February 7, 1523.

To all whom it may concern:

Be it known that 1, JOHN E. 'GHALMAN, a citizen of the United States, residing at Chicago, in the county of Cook, State of- Illinois, have invented certain new and useful Improvements in Looper-Thread Controllers for Sewing Machines, of which the following is a description, reference being had to the accompanying drawing and to the figures of reference marked thereon.

Theinvention relates to newand useful improvements in thread controls for sewing machines, and more particularly to a looper thread controller for a sewing" machine. hav ing a looper moving back and forth in the general direction of the line of feed and moving in a direction opposed to the feed when entering the'necdle thread loop.

An objectof the invention is to provide a thread cont-rolling mechanism for a looper mechanism of the above type wherein slack forming in the looper thread is taken up just prior to the retracting movement of the looper so as to prevent undue slack in the looper thread at this time, which slack is liable to disturb the proper position of the looper thread between the eyeof the looperand the material at the timeiwhen the g needle point passes the looper thread, and 30 thus to insure that the needle point will pass between the looper thread and the body of the looper. p

In the drawings'which'show by way of illustration one embodiment of the invention'' a Figurel is aside view of a sewing machine embodying my improvements;

I Fig. 2 is a plan view of the parts beneath the work support with the feed dogs broken away to showthe loopers beneath the same; Fig. 3 is a perspective view showing the threads and thread controllers for both the needles'andfthe loopers;

' Fig. 4 is a View showing more or less diagrammatically the position ,of the thread controlling elements when the looper is at therear end ofits stroke;

ig. 5 is a'similar View butv when the looper isat the forward end of its stroke, and Fig. 6 is a similar View but showing the position of the thread controlling elements when the needle point is passing the looper thread.

'The machine to which I have applied my Serial No. 617,557.

said patent may be had for a full disclosure 7 thereof. It ispointed out, however,that the machine includes a work support 1, an overhanging arm 2, a needle bar 3, Which is reciprocated by a needle lever 4. through a link connection 5. The needle bar carries four needles indicated at 6. The needle threads for the needles are indicated at (1. These needle threads run through tensions 7 carried by a bracket 8 on the overhanging arm, thence through eyes in a thread arm 8?, thence through a thread arm 9 on the needle lever 4, thence through a thread eye 10 carried. by a lever 11 which in turn is connected to the pre-sser bar of the sew-. ing machine so as to be moved up and down by the, presser bar. The threads then pass through thread eyes in an arm 12 carried by the needle lever and thence through thread eyes in an arm 13 carried by the needle bar. The threads are then led under a tension plate letand from this point pass to'the. eyes of the needles. The needle lever 4 is oscillated by a pitman 15 which cooperates With an eccentric on the' main shaft 16. This main shaft 16 islocated beneath the work support. The material is fed across the work support by feed dogs 17 carried by a feed bar which is moved back and forth'and raised and lowered so that the feed dogs are brought into engagement with the material for feeding the same, and thence moved out of engagement with the material for their return stroke.

Cooperating with the needles beneath the work support are loopers 18. There is a looper for each needle and these loopers are provided with an eye at the heel and at the point, and are known as thread carrying loopers. These loopers are mounted in a looper carrier 19 which in turn is mounted on a shaft 20. The carrierxis preferably connected to the shaft 20 so thatit be moved endwise for bringing the loopers to a point at one side of the throat plate for threading. given a slight endwise movement by means This shaft 20 is'oscillated and of a lever 21 which is oscillated by a pitinan 22 cooperating with the eccentric on the main shaft 16. Rigidly carried by the end of the shaft is an arm 23 having a ball on the end thereof. As clearly shown in the patent, there are. devices 24 between the lever 21 and the arm 23 which impart an oscillation to the shaft 20, and a slight endwise movement to the shaft 20. The result of this movement is that the looper is moved in a curved path forward and backward following the same path in its rearward movement as in its forward movement. This curved path is so disposed relative to the needle and the loopers are so timed, that the looper thread is carried to the opposite side of the path of. the needle from that traveled by the looper as the needle passes the looper. As a result, the needle passes between the looper thread and the body of the looper as clearly set forth in the patent above referred to. The loopers are given a dwell at the forward end of their strokes, and thus a very short stroke looper can be used.

The looper threads are indicated at 25. There is a looper thread for each looper. These looper threads pass through tensions 26 carried by thelnacket 3, and there, of course, is a tension for each looper thread. The looper threads then pass through thread eyes in the outer end of the arm 8* and thence between thread guiding wires 27. These thread guiding wires 27 are formed with a looped portion 28, and a screw 29 passing through the looped portion into the overhangin arm of the machine serves to adjustably secure the thread guiding wires 27 in a stationary position. The looper, threads pass in a substantially vertical line from the eyes in the arm 8 to the thread guiding wires 27. Secured to the base of the machine is a bracket 30. This bracket is provided with slots 31 through which screws 32 pass so that the bracketinay be adjustably secured to the bed plate of the machine. The bracket is provided with a standarc 33 in which is mounted a short shaft 34. Secured to the outer end of this short shaft 34 is a sleeve 35 in which is mounted an arm 36. The arm 36 extends upwardly, thence laterally, and is then bent back upon itself to form a member 37 which is substantially parallel with the axis of the shaft 34. The member 37 is provided with thread guiding eyes 38 through which the looper threads 25 pass. Secured. to this member 37 and extending upwardly therefrom is an arm 39. This arm 39 is bent laterally to provide a section 40 which is substantially parallel with the member 37 and said section 40 lies substantially in a plane passing through the member 37 and the aXis of the shaft 34. This arm engages the looper threads when the shaft 34 is oscillated. The looper threads run in a hori zontal direction from the thread guiding eyes 38 over a thread wire 41 and thence through a channel 42 and underneath a guide arm 43 to the loopers. Two of the threads run through a guide 44 before pass ing to the heel of the looper, while the other threads run directly to the heel of the loopers.

It will be noted that the loopers move in a plane substantially at right angles to the run of the looper threads from the channel 42. The shaft 34 is oscillated by means of a link 45 which is connected at 46 to' an arm 47 carried by the shaft 34. The link is also connected at 48 to theneedle lever extension 49. The link is so disposed that when the loopers are at the rear ends of their strokes, the point 48 of connection between the link and the needle lever extensions is substantially in alinement with the point 46 where the link is connected to the arm 47 and the fulcrum 50 of the needle lever. Said point of connection 48 moves to the right of said line a slight distance and this gives a substantial dwell to the thread arm when the needles are at the lower ends of their strokes. 7 At this time, the loopers are at the rear ends of their strokes.

The operation of my device is as fol.- lows When the loopers are at the rear ends of their strokes, the thread controller is at the extreme right=hand end of its stroke and all theslack has been taken out of the thread by the movement ofthe thread guide bar 37 to the right. As the loopers move forward; into their needle thread loops, slack will be given to the looper thread in'view of the fact that this threadguide bar 37 moves toward the loopers, and, the thread running from the source of supply to said threadguide bar 37 is substantlally vertical. The position of the thread controlling parts whenthe looper is at the rear end of its stroke is shown in Fig. 4 of the drawings. When the loopers reach the forward end of their stroke, they come to a dwell, and while they are at a dwell, the thread controlling bar 40 continues its forward movement as clearly shown in Fig. 5., bending the looper threads so as to take slack out of the looper threads. l/Vhen the loopers start on their retracting movement, this thread bar 40 moves to the right, thus giving up slack, but at the same time, some slack will be taken. up by thethread guide bar 37 moving to the right, so that the slack in the looper threads create-d at the time when the loopers are at the forward end of their stroke and just prior to the retracting movements thereof is under the control of this thread guide bar 40 which takes up some of this slack and prevents the surplus slack forming in the looper threads. In the type oflooper mechanism disclosed, it is very essential that the looper thread running from the eye of the looper to the material shall be substantially straight so that the needle point may pass on the right side of the thread whereby when it continues its outward movement, it will pass between the looper thread and the body ofrthe looper. It is well understood that in a rapidly operating machine, such as a sewing machine, making from fifty to sixty stitches per second or the like, that the slack in the thread at one portion thereof will influence the condition of the thread at another portion thereof at a later time in the cycle. In other words, if there is too much slack in the looper thread, just before the looper starts to retract, the influence of this surplus slack will act on the thread between the eye of the looper and the material after the looper starts back, and it is to prevent this accumulation of so much slack that the thread between the eye of the looper and the material will be influenced in such a way as to cause the skipping of stitches. By my improved looper thread controlling mechanism wherein the slack in the looper thread between the eye of the looper and the supply is taken up to a certain extent before the looper starts to retract, I am able to secure the proper position of the thread between the eye of the looper and the material at the critical time when the point of the needle is passing the looper thread. v

It is obvious that minor changes in the details of construction and the arrangement of the parts may be made without departing from the spirit of the invention as set forth in the appended claims.

Having thus described the invention, what I claim as new'and desire to secure by Letters-Patent, is i 1. The combination with a'feeding mechanism, a thread carrying looper moving in the general direction of the line of feed and opposed tothe direction of feed as it enters the needle thread loop; of a thread controlling mechanism for the looper including a thread engaging arm, thread guides cooperating therewith, and means for moving said arm so as to engage the looper thread and take up a portion of the surplus slack therein just before the looper begins its retracting movement.

2. The combination with a feeding mechanism and a thread carrying looper moving in the general direction of the feed and opposed to the feed when entering the needle thread loop, said looper having an extended dwell at the forward end of its stroke; of a looper thread controlling mechanism including a thread arm, andmeans for moving said thread arm into engagement with the looper thread while thelooper is at a dwell for taking up some of the surplus slack in the looper thread just prior to the retracting movement of the looper.

3. The combination with a feeding mechanism, a thread carrying looper moving in the general direction of feed and opposed to the feed when entering the needle thread loop, said looper also moving back and forth in substantially the same path, and laterally as'well as forwardly so as to carry its thread on to the opposite side of the path of the needle from that passed by the looper; of a thread controller for the looper thread including a thread arm, guides cooperating therewith, and means for moving said thread arm whereby the same is caused to engage the looper thread and take up. surplus slacktherein just prior to the retracting movement of the looper.

4. The combination with a feeding mechanism, a thread carrying loo-per moving in the general direction of feed and opposed to the feed when entering the needle thread loop, said looper also moving back and forth in substantially the same path, and laterally as well as forwardly so as to carry its thread on to the opposite side of the path of the needle from that passed by the looper, said looper having a dwell at the forward end of its stroke; of a thread controller fort-he looper thread including a thread arm, guides cooperating therewith, and means independent of the looper opera-ting mechanism for moving said thread arm and for causing the same to engage and take up surplus slack in the looper thread while the looper is at a dwell. 1

In testimony whereof, I affix mysignature.

' JOHN E. CHALMAN. 

